Development and validation of an immunosensor for monocyte chemotactic protein 1 using a silicon photonic microring resonator biosensing platform.

We report the development of an optical immunosensor for the detection of monocyte chemotactic protein 1 (MCP-1) in serum samples. MCP-1 is a cytokine that is an emerging biomarker for several diseases/disorders, including ischemic cardiomyopathy, fibromyalgia, and some cancers. The detection of MCP-1 was achieved by performing a sandwich immunoassay on a silicon photonic microring resonator sensor platform. The resonance wavelengths supported by microring sensors are responsive to local changes in the environment accompanying biomarker binding. This technology offers a modularly multiplexable approach to detecting analyte localization in an antibody-antigen complex at the sensor surface. The immunosensor allowed the rapid detection of MCP-1 in buffer and spiked human serum samples. An almost 2 order of magnitude linear range was observed, between 84.3 and 1582.1pg/mL and the limits of blank and detection were determined to be 0.3 and 0.5pg/mL, respectively. The platform's ability to analyze MCP-1 concentrations across a clinically-relevant concentration range was demonstrated. A silicon photonic immunosensor technology was applied to the detection of clinically-relevant concentrations of MCP-1. The performance of the sensor was validated through a broad dynamic range and across a number of suggested clinical cut-off values. Importantly, the intrinsic scalability and rapidity of the technology makes it readily amenable to the simultaneous detection of multiplexed biomarker panels, which is particularly needed for the clinical realization of inflammatory diagnostics.